Re: BUG: unable to handle kernel paging request in kvm_cpu_has_pending_timer

[Dmitry Vyukov]

On Mon, Dec 4, 2017 at 1:25 PM, syzbot
<bot+f8b526f284f9ef5f5e94b22cfb48130806bc7126@xxxxxxxxxxxxxxxxxxxxxxxxx>
wrote:
> Hello,
>
> syzkaller hit the following crash on
> fb20eb9d798d2f4c1a75b7fe981d72dfa8d7270d
> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master
> compiler: gcc (GCC) 7.1.1 20170620
> .config is attached
> Raw console output is attached.
>
> Unfortunately, I don't have any reproducer for this bug yet.
>
>
> BUG: unable to handle kernel paging request at 00000000a570cd8a
> IP: arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline]
> IP: static_key_false include/linux/jump_label.h:142 [inline]
> IP: lapic_in_kernel arch/x86/kvm/lapic.h:151 [inline]
> IP: kvm_cpu_has_pending_timer+0xd/0x70 arch/x86/kvm/irq.c:36
> PGD 5e28067 P4D 5e28067 PUD 5e2a067 PMD 0
> Oops: 0002 [#1] SMP KASAN
> Dumping ftrace buffer:
>    (ftrace buffer empty)
> Modules linked in:
> CPU: 1 PID: 5201 Comm: syz-executor5 Not tainted 4.15.0-rc1-next-20171201+
> #57
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> task: 00000000c02a78de task.stack: 00000000d671e50e
> RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline]
> RIP: 0010:static_key_false include/linux/jump_label.h:142 [inline]
> RIP: 0010:lapic_in_kernel arch/x86/kvm/lapic.h:151 [inline]
> RIP: 0010:kvm_cpu_has_pending_timer+0xd/0x70 arch/x86/kvm/irq.c:36
> RSP: 0018:ffff8801c666f698 EFLAGS: 00010216
> RAX: 0000000000010000 RBX: ffff8801c5bf8c00 RCX: ffffffff8115ae3d
> RDX: 00000000000026ca RSI: ffffc90003a7b000 RDI: ffff8801c5bf8c00
> RBP: ffff8801c666f6a0 R08: 0000000000000001 R09: 0000000000000002
> R10: 0000000000000000 R11: ffffffff8748cd60 R12: 0000000000000001
> R13: dffffc0000000000 R14: ffff8801c5bf8c30 R15: ffff8801c5bf8c00
> FS:  00007fb6c7f4e700(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: fffffffffffffff8 CR3: 00000001cf45c000 CR4: 00000000001426e0
> Call Trace:
>  vcpu_run arch/x86/kvm/x86.c:7155 [inline]
>  kvm_arch_vcpu_ioctl_run+0x53e/0x5c60 arch/x86/kvm/x86.c:7314
>  kvm_vcpu_ioctl+0x64c/0x1010 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2574
>  vfs_ioctl fs/ioctl.c:46 [inline]
>  do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:686
>  SYSC_ioctl fs/ioctl.c:701 [inline]
>  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
>  entry_SYSCALL_64_fastpath+0x1f/0x96
> RIP: 0033:0x4529d9
> RSP: 002b:00007fb6c7f4dc58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 00000000004529d9
> RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000015
> RBP: 0000000000000589 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f5578
> R13: 00000000ffffffff R14: 00007fb6c7f4e6d4 R15: 0000000000000000
> Code: 41 ff ff ff 4c 89 f7 48 89 55 d0 e8 4e 1f 91 00 48 8b 55 d0 e9 fc fe
> ff ff 90 90 90 90 90 55 48 89 e5 53 48 89 fb e8 03 8c 5a 00 <cc> 1e 00 00 00
> e8 f9 8b 5a 00 e8 f4 8b 5a 00 48 89 df e8 ac e9
> RIP: arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline] RSP:
> ffff8801c666f698
> RIP: static_key_false include/linux/jump_label.h:142 [inline] RSP:
> ffff8801c666f698
> RIP: lapic_in_kernel arch/x86/kvm/lapic.h:151 [inline] RSP: ffff8801c666f698
> RIP: kvm_cpu_has_pending_timer+0xd/0x70 arch/x86/kvm/irq.c:36 RSP:
> ffff8801c666f698
> CR2: fffffffffffffff8
> ---[ end trace e304b48527225e98 ]---
> Kernel panic - not syncing: Fatal exception
> Dumping ftrace buffer:
>    (ftrace buffer empty)
> Kernel Offset: disabled
> Rebooting in 86400 seconds..

#syz dup: BUG: unable to handle kernel paging request in __switch_to

> ---
> This bug is generated by a dumb bot. It may contain errors.
> See https://goo.gl/tpsmEJ for details.
> Direct all questions to syzkaller@xxxxxxxxxxxxxxxxx
> Please credit me with: Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
>
> syzbot will keep track of this bug report.
> Once a fix for this bug is committed, please reply to this email with:
> #syz fix: exact-commit-title
> To mark this as a duplicate of another syzbot report, please reply with:
> #syz dup: exact-subject-of-another-report
> If it's a one-off invalid bug report, please reply with:
> #syz invalid
> Note: if the crash happens again, it will cause creation of a new bug
> report.
> Note: all commands must start from beginning of the line in the email body.
>
> --
> You received this message because you are subscribed to the Google Groups
> "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxxx
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/syzkaller-bugs/001a1145ac54aee959055f82ce64%40google.com.
> For more options, visit https://groups.google.com/d/optout.